1. Field of the Invention
This invention relates to an alarm monitoring system and more particularly relates to an engine system for monitoring a variety of conditions and alerting the operator to an abnormal condition of any or all of them.
2. General Background
In the present state of the art, alarm monitoring systems used to monitor the conditions of various engine systems and other general systems such as on ships, trains, and deisel trucks suffer from a variety of drawbacks.
A large marjority of systems presently in use are provided with a flashing light to indicate an abnormal condition of a particular system or function being monitored and may be used in conjunction with or without an audible alarm. Upon acknowledgement of the alarm condition by the operator, the system circuitry will cause the light to stop flashing and transfer to a constant bright glowing condition with any audible alarm being deactivated. This presents a particular problem during night time operations as it is well known that any bright lights will have a detrimental effect on night vision. This can prove to be hazardous to the operators of such vehicles as ships, trains or trucks.
Problems encountered with solid state circuitry using printed circuit boards include the following: it often does not stand up well to vibrations encountered in the above operating conditions; it is difficult to trouble shoot for those inexperienced in electronics; and the necessary equipment for trouble shooting is often not present. Normally, each circuit must be tested individually and in sequence. Sequencing may be disturbed if the system is shut down and then re-activated and a separate mode must often be switched to for testing purposes.
Alarm or monitoring systems of which applicant is aware include the following:
U.S. Pat. No. 3,292,568 entitled "Protective Circuit For Boats" teaches an electrical protective system which forms a part of the starting circuit for an internal combustion engine and a monitoring circuit for a boar that has a plurality of alarms for various functions. The circuitry includes a detector for sensing dangerous concentrations of fuel vapor and a time delay relay for delaying the operation of the engine for a predetermined time after the ignition switch is closed. A blower, which operates during the time delay period and is automatically controlled, operates at all times when fuel vapors are sensed and is included in the circuitry to remove fuel vapor from the boats bilge compartments so that the hazard of fire and/or explosion is minimized when starting the engine. A pair of relay switches are placed in series with the engine starter switch with the relays being closed to complete the circuit to the starter only when fuel vapor is not being sensed and after the time delay period is lapsed. The device further provides buzzers and a series of lights to give both an audible and visual indication of the conditions of the engine being monitored. While this patent teaches circuitry which monitors various fuctions of a boat engine and a buzzer and a series of lights to give both audible and visual indication of the conditions monitored, it does not include the testing and acknowledging circuitry of the present invention.
U.S. Pat. No. 4,037,578, entitled "Ignition Safety Control System" discloses a digital solid state safety control system which is operatively connected to control the energization of the ignition coil and starter motor of one or more internal combustion engines and the energization of one or more exhaust blowers in ventilating communciation with the engine compartment. A central unit houses the control circuits of the system and is adapted to be connected to safety and warning indicator lights on the control panel.
U.S. Pat. No. 3,599,591, entitled "Safety Lockout Ignition System" discloses an ignition system for power boats for preventing explosions in the engine compartment thereof. The device has time delay relays in series which are connected to a latching relay between the battery and the engine and between the start terminal of the ignition switch and the starter to prevent the engine from being started until blowers have operated for a pre-selected time duration to clear the engine compartment of dangerous fumes. The control latching relay energized by the starter energizes the shut-off time-delay relay after a second predetermined time duration from starting to open the normally closed contacts of a shut-off latching relay halting the operation of the blowers after they have cleared the engine compartment of any fumes which may have accumulated during the starting of the engine.
U.S. Pat. No. 4,214,227, entitled "Instrument Panel Assembly" discloses an instrument panel assembly having a plurality of indicating elements to indicate the condition of several engine systems being monitored and a test switch for concurrently indicating the operability of the individual indicating elements. The indicating elements are indicating lamps which alert the operator to an abnormal condition. This invention is aimed at providing the operator with a means of checking the operability of the indicator lamps to prevent damage to the equipment due to a burned out lamp or a loose connection from preventing the operator of receiving notice of an abnormal engine condition and is aimed at the commercial automobile field.
U.S. Pat. No. 4,231,073, entitled "Automatic Improved Engine Control System Containing Both Solid State Circuits And Relays" discloses solid state circuitry which includes a cranking module for activating and deactivating the cranking of the engine, an overcrank module having time delay circuitry which detects when an overcrank has occurred, reset circuitry which resets the cranking and overcrank module after the engine is started, time delay circuitry which delays fault condition engine shutdown where low oil pressure is indicated and start up circuitry which prevent a false alarm condition at the initiation of the system. This invention utilizes complex solid state circuitry having transistors and digital logic circuitry which is aimed at a different purpose than that of the present invention.
U.S. Pat. No. 4,041,451, entitled "Circuit For Monitoring The Operativeness Of Current Consuming Electrical Devices" discloses a monitoring circuit adapted for use in automotive vehicles especially for monitoring the operation of an electrical device, with an inert-gas read switch used to monitor current flow through electrical devices and provide an indication thereof. An example of electrical devices monitored in an automobile includes tail lights.
U.S. Pat. No. 2,679,641, entitled "Pneumatically Actuated Anti-Overflow Alarm And Safety Device For Tankers" discloses a means for avoiding overflow of the individual tanks of oil tanker vessels during the loading operation. Increased air pressure flowing from a bell causes a bellows to trip an alarm thus warning of a possible overflow condition in one of the tanks in the ship. The system utilizes a simple alarm trip system and provides no indication of which tank is approaching an overflow condition.